1. Field of the Invention
The present invention relates to a linear guide apparatus which includes a clamp device built therein for preventing the fall-off of a slider and a guide rail, and for securing the slider to the guide rail if necessary.
2. Description of the Prior Art
A linear guide apparatus with a clamp (or lock) device of this type is disclosed, for example, in U.S. Pat. No. 4,417,771.
In this apparatus, both lateral side surfaces of an upper half part of a guide rail are slanted downwardly and inwardly to a marrow width so as to form slant surfaces (substantially inverted-trapezoidal cross section). On the other hand, a side surface slide member having a cross section of a substantially inverted-right-angled triangle and having a slant surface matched with the slant surface of the guide rail is fitted to each of the inner surfaces of both side walls of the slider (bearing) which is straddlingly mounted on the guide rail.
Furthermore, the slider is formed with a pair of through holes and a clamping female screw at an intermediate position between the through holes in each lateral side. Thus, by screwing a male screw which engages the female screw, the side slide member mounted in an inner bore of the slider is pressed against a slide surface of the guide rail to clamp the slider to the guide rail.
Accordingly, even when the apparatus is used in an inverted condition by securing the guide rail to a ceiling and the slider hanging therefrom, and even when no balls are provided in the slider to which an object to be carried is mounted, since the lateral side surfaces of the guide rail engage the slant surfaces of the side surface slide members fitted to the side walls of the slider, fall-off of the slider is prevented and the safety is insured.
Furthermore, when a cutter holder is mounted on the slider and machining is performed by stopping the cutter holder at a predetermined position along the guide rail, the male screw is advanced by turning a handle of the clamp device to press a center portion of the side slide member. As a result, the side slide member is curved and the center portion protrudes inwardly and presses against the slant surface of the guide rail. In this manner, the slider is clamped to the guide rail and the cutting can be performed with high accuracy.
However, in the prior art apparatus, a problem exists in that since the lateral side surfaces of the guide rail are formed as slant surfaces, and since the slant surfaces serve as reference surfaces, it has been very difficult to machine rolling grooves for filling members therein with high accuracy.
Furthermore, another problem exists in that since the fall-off preventing device and the clamp device are formed as separate members, the number of parts is increased and the structure becomes more complex.
Moreover, another problem exists in that since the clamp device is manipulated by the handle, a remote operation is impossible, and when the apparatus is used in a travelling condition along a ceiling, the clamping cannot be performed as required.